道路绿化隔离带消减颗粒物效应及配置参数研究

交通污染已成为城市空气颗粒物污染的主要来源之一,对居民的生活、工作、出行产生了严重影响,而绿化隔离带可作为优化非机动车道和人行道空气质量的一种有效且经济地措施。基于实验测定评价道路绿化隔离带对非机动车道空气颗粒物浓度的影响,并提出分层疏透度来表征样带垂直结构特征,分析绿化隔离带配置方式对街道空气颗粒物浓度的影响。研究结果显示,绿化隔离带可较好地改善街道空气质量,对TSP和PM_(10)的消减效果较PM_(2.5)好;颗粒物的消减效果与样带的植物配置结构有紧密联系,分析结果显示颗粒物消减效率均与0～2m高度区间内的疏透度呈显著负相关。在交通流量较大的城市干道上,应该减少或者避免使用冠大荫浓的高大乔木,多配置结构紧密和叶密度较大的灌木植物。本研究结果可为城市道路绿化参数化设计和优化提供理论支撑,为改善人居生活环境作出贡献。

The Removal Effect of Street Vegetation Barriers to Particle Matters and Correlation with Configuration Parameters

Traffic-related air pollution has become a main source of urban air particle matters (PM) and brings serious influence to residents'' living, working and traveling, and street vegetation barriers could act as a cost-effective way to improve near-road air quality. This investigation assessed the attenuation effect of street vegetation barriers to air PM through field experiment, proposed layer shelterbelt porosity to describe the vertical characteristics of vegetation barriers, and analyzed the influence of vegetation barriers configuration to PM concentration. The results indicated that vegetation barriers can effectively improve street air quality, and the removal effect of TSP and PM10 was better than that of PM2.5. The PM removal effect was closely correlated with the configuration characteristics of vegetation barriers, and the PM removal efficiency was significant negative correlated with the porosity of 0~2m section. Big trees should be decreased or avoided within the street with serious traffic volume, while dense shrubs or hedges should be advocated. These results could provide theory basis for the parameter design of street vegetation barriers, and could contribute to the improvement of living environment.